Roco Breakdown Crane

Hi All



FOOD for THOUGHT



I have been given a Roco 46900 breakdown crane , which is for a 3 rail system .

 I would like to convert this to a 2 rail system . I am hoping that I can remove the centre pick up

and alter the wheel pick ups . without too much trouble .

 OR set up an independent track , isolated from the existing layout , solely for the use of the crane .

 Has any body any ideas how I might achieve either of the above .

 Regards Ted



 

Hi Ted

There are guys on the O scale forum who are doing it all the time.

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Cheers

Thanks Max ,
 I will have a look
 Regards Ted

Hi Ted,

3 rail pick-up means all wheels are live and connected to one terminal of the normally isolated motor (one polarity), the central pick-up shoe is connected to the other terminal of the motor. If it has a metal body this is also live (and often connected directly to one terminal of the motor).

Minimum required is to isolate one wheel on each axle, and arrange electrical pick-up from the rims in the normal manner. Best bet is to ask Roco for an insulated wheel set as it would be doubtful if anything from the UK will have the correct axle and wheel diameter. They will have one as they produce a 2-rail and a 3-rail version.

However, I believe that Roco 46900 breakdown crane has an AC motor lurking inside (it was designed to run on the Marklin 3-rail AC system and has an inbuilt digital controller). If so you will also need a new motor (or 3) to run it with DC or 2 rail DCC. You would then have to address the issue of replacing the integrated digital controller with a DCC controller so you can control the 3 independent motors. Again, best bet is Roco.

Running independently it will need a separate AC power source bus and controller (and some rails). Plus an engine (and decoder) to pull it around. Which might be the only way to get it to run properly.

Pandora's box situation. Either way is likely to be expensive (anything Roco/Marklin is expensive compared to Bachmann/Hornby).

Nigel

Hi  Nigel & Max

Thank you for your replies .

 I realise that I will need to disconnect the centre rail pick up ,

 and connect the two sets of existing wheel pick ups together.

 Then connect the centre rail pick up to the other wheel pick ups .

 There three AC motors within the crane . WILL these motors run on DCC ?

 I have a couple of Walthers  180629  AC motors that run quite happily on dcc.

 Regards Ted

 



 

Hi Ted,

I believe AC means Marklin DCC control (Motorola protocol), which from what I've read is not compatible with NMRA DCC. Seems you need an AC power source and an appropriate AC decoder (which might be dual function Marklin/NMRA protocols after 2010-12). Plus the controller which is not AC or DC specific. You could replace the embedded decoder with an AC compatible decoder such as an ESU V4, but whether this would be able to control the 3 motors and accept regular DCC power is something you would have to ask about.

If you are in luck those motors are actually small DC ones, that proprietary AC decoder with the Motorola protocol may simply be taking an AC input and outputting DC to the motors via the appropriate cv's/functions. Question would be is the 150-200 mA output of the auxillary outputs in a conventional DCC decoder enough to drive the motors. If the Roco decoder is switching 1A between the motors it could get complicated. I have a feeling those motors could be 6v DC ones (or even 3v DC) given the space available. The DCC version uses a Lenz decoder and a combination of F0/F1 functions to rotate and elevate/depress, so it's low current DC.

The surest way is probably to replace the control system inside with a Roco 2-rail conventional DCC setup. I would ask Roco what it would take to operate on 2 rail DCC before going any further - roco@roco.cc is the technical department. Whether they have anything re parts could be an issue. Maybe they thought about this and made it an easy conversion (a decoder swap). Then again…

Murky waters. Try the ESU group on Yahoo groups to see if anybody has done it. I still think the easiest solution is a length of track (3 rail or 2 if you switch the shoe pick-up to one set of wheels), an AC power source and the controller. 

I have a feeling it might be one of those difficult conversions that end up costing as much as the model would have been. Then again, if it's just a case of swapping decoders and altering the pick-up from 3 rail AC to 2 rail DCC, it could be really easy.

Nigel

Hi Nigel

 I have been doing some research , and have found that the

 Roco  crane can be converted . Unfortunately the cost in doing so

 is astronomical . now I will have to decide weather to us it as a

 static display , or put it on the market .

 I would like to thank you again for your help

 Regards

 Ted

Hi Ted,

I thought it might turn out to be an expensive conversion. Pity, it's an interesting model.

Nigel